I am looking to fix a cheap dinner for 3 tonight, but I want to cook something that I can take into work with me tomorrow. The only problem is there isn't a microwave so it will need to be eaten at room temp.

I was thinking about cooking a cut of beef and using the leftovers for a sandwich. Preferably not a pulled pork because it will take too long to cook tonight. I am not vary good with various cuts of meat, any ideas? Thanks